The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines combust a mixture of air and fuel to produce torque. Exhaust gas resulting from the combustion is passed through an exhaust system before exiting to the atmosphere. Typically, the exhaust system includes an oxygen sensor that measures oxygen levels in the exhaust gas. An air/fuel (A/F) ratio of the engine is determined based on the oxygen levels, and the engine is controlled based on the A/F ratio.
Over time, particles from the exhaust gas may build up on an oxygen sensor, increasing the response time of the oxygen sensor. The response time of an oxygen sensor is the amount of time that elapses after a change in the A/F ratio before the oxygen sensor responds to the change in the A/F ratio. Eventually, deposits on the oxygen sensor may completely diminish the ability of the oxygen sensor to detect oxygen. The oxygen sensor may be replaced when the response time exceeds an acceptable limit or when the ability of the oxygen sensor to detect oxygen is completely diminished.